(The following appeared on the Washington Post website on April 23, 2011.)

BEIJING — China’s expanding network of ultramodern high-speed trains has come under growing scrutiny here over costs and because of concerns that builders ignored safety standards in the quest to build faster trains in record time.

The trains, a symbol of the country’s rapid development, have drawn praise from President Obama. But what began in February with the firing and detention of the country’s top railway official has spiraled into a corruption investigation that has raised questions about the project’s future.

Last week, the new leadership at the Railways Ministry announced that to enhance safety, the top speed of all trains was being decreased from about 218 mph to 186. Without elaborating, the ministry called the safety situation “severe” and said it was launching safety checks along the entire network of tracks.